1993 Mercedes-Benz 300 — MOT failures & pass rate
1,271 MOT tests on the 1993 Mercedes-Benz 300 are in this dataset, and 80.7% of them passed. Against all cars of a similar age (23.4% fail rate), the 1993 300 comes out 4.1pp better. Failures cluster in lighting & signalling, suspension and brakes.
What the MOT record shows
Lighting & signalling dominates the failure mix at 12.3% of all tests — 4.6 points clear of suspension, so it is the first thing to check.
At component level the recurring items are headlamp aim, position lamp and catalyst emissions — headlamp aim alone was recorded 56 times.
Condition tracks the odometer closely. Failures run at 10.1% in the 30-60k band and 27.1% in the 150k+ band, a 17.0-point spread — more than double.
Advisories point at the next bill rather than this one: suspension was flagged on 26.8% of tests without failing them.
The trend is improving — the fail rate fell from 20.1% in 2021 to 17.4% in 2025, as the worst-kept examples leave the fleet.
How it compares
Top failure categories
| # | Category | % of tests affected | Tests |
|---|---|---|---|
| 1 | Lighting & signalling | 12.3% | 157 |
| 2 | Suspension | 7.7% | 98 |
| 3 | Brakes | 6.9% | 88 |
| 4 | Body, structure & corrosion | 5.7% | 72 |
| 5 | Emissions & environmental | 3.7% | 47 |
| 6 | Visibility | 3.3% | 42 |
Most common specific failures
The exact components most often recorded as failures — more specific than the categories above.
| # | Failure item | Times recorded |
|---|---|---|
| 1 | Headlamp aim | 56 |
| 2 | Position lamp | 53 |
| 3 | Catalyst emissions | 45 |
| 4 | Rigid brake pipes | 44 |
| 5 | Component mounting prescribed areas | 38 |
| 6 | Track rod end | 34 |
Top advisory categories
Advisories aren't failures, but they flag work likely needed soon — useful when budgeting.
| # | Category | % of tests with advisory | Tests |
|---|---|---|---|
| 1 | Suspension | 26.8% | 341 |
| 2 | Brakes | 24.8% | 315 |
| 3 | Emissions & environmental | 15.9% | 202 |
| 4 | Tyres | 13.9% | 176 |
| 5 | Body, structure & corrosion | 10.8% | 137 |
| 6 | Steering | 9.8% | 124 |
Failure rate by mileage
Higher-mileage cars tend to fail more — often the most useful guide to real condition.
| Mileage band | Tests | Fail rate |
|---|---|---|
| 30-60k | 109 | 10.1% |
| 60-90k | 154 | 10.4% |
| 90-120k | 312 | 17.3% |
| 120-150k | 255 | 19.2% |
| 150k+ | 421 | 27.1% |
By fuel type
| Fuel | Tests | Fail rate |
|---|---|---|
| Petrol | 809 | 17.1% |
| Diesel | 462 | 23.2% |
Trend over time
| Dataset year | Tests | Fail rate |
|---|---|---|
| 2021 | 309 | 20.1% |
| 2022 | 273 | 20.9% |
| 2023 | 257 | 20.2% |
| 2024 | 225 | 16.9% |
| 2025 | 207 | 17.4% |
What to check before buying a 1993 300
On a 1993 300, lighting & signalling is what the MOT record says goes wrong most — it appeared in 12.3% of tests. Check these areas before you commit.
- Lighting & signalling (12.3% of tests): Often a cheap bulb, but persistent issues can mean wiring or corrosion in the units. Typical repair: £10–£150.
- Suspension (7.7% of tests): Worn drop links, bushes, springs or shocks — listen for knocks over bumps and check for uneven tyre wear. Typical repair: £150–£450 per corner.
- Brakes (6.9% of tests): Pads/discs are routine wear; binding, imbalance or corroded pipes are more serious — test for pulling under braking. Typical repair: £100–£350 per axle.
Repair costs are rough UK ballpark ranges to set expectations, not quotes — actual prices vary widely by car, parts and garage.
Frequently asked questions
How many 1993 Mercedes-Benz 300s pass their MOT?
80.7% of the 1,271 1993 Mercedes-Benz 300 MOT tests in this dataset passed — a 19.3% fail rate.
What is the most common MOT failure on a 1993 Mercedes-Benz 300?
Lighting & signalling, recorded in 12.3% of tests, followed by suspension (7.7%).
Does the 1993 300 get worse with mileage?
Its MOT fail rate rises from 10.1% in the 30-60k band to 27.1% in the 150k+ band.
Methodology & source. Based on 1,271 MOT tests. Dataset: DVSA MOT testing data (2021,2022,2023,2024,2025). Data last updated 2026-07-27. Figures reflect MOT-testable defects only — read the methodology for how these are calculated and what they don't measure.